Simple Mobile Phone Detector Circuit using Op-Amp

Overview: Mobile Phone Detector Circuit
Mobile Phone Detector
is a Circuit that detects the presence of
Mobile Phone
up to a certain range like 1.5 meter . It detects the phone when an
incoming call
or
outgoing call
is made or when an
SMS is sent
or
received
or any
GPRS used
When the circuit detects an
RF signal
from an activated mobile phone, it gives an indication by
switching ON
an
LED
. The LED will start blinking and continues to blink until the
incoming/outgoing signal
stops.
Mobile Phone detector
can also be called as a Frequency Detector.
Frequency Detector
is simply a
Current to Voltage Converter Circuit
which detects the frequencies in between the range of about
800 MHz to 3GHz
Bill of Materials
Following are the components required for making this project. All the components can be easily purchased from Amazon.
S.N.
Components
Description
Quantity

LM358
Dual Op-Amp IC

Resistor
1 KΩ

Resistor
100 K Ω

Resistor
220 K Ω

Potentiometer/Trimmer
2.2 M Ω

Capacitor
1 µF, 16V (Electrolytic Capacitor)

Capacitor
100 µF, 16V (Electrolytic Capacitor)

BC548
NPN Transistor

LED
5mm Any Color

Antenna
15cm Single Strand Wire Antenna

Power Supply
4.5V Battery/Adapter

Mobile Phone Detector Circuit using Op-Amp
This circuit consists of an op-amp with some active-passive components. A LED is used for an indication of the presence of a cellphone. Op-amp is configured as Frequency Detector and its output is connected to a LED using NPN Transistor. The circuit diagram is given below. The circuit can be either assembled in a breadboard or in a Vero Board.
The circuit is built using
LM358 Op-Amp
IC and NPN Transistor
BC548
. You can check our previous project based on LM358 IC:
Over Heat Detector
When a mobile phone is active, it radiates RF signal in the form of electromagnetic radiation. When the mobile phone radiates energy in the form of RF signal, Capacitor C2 absorbs it and used as an input to LM358 IC. The output of LM358 is connected to LED via Transistor which gets turned ON. Then the flashing of LED is observed. The potentiometer RV1 is used to adjust the sensitivity or range of the circuit. This is how you can make a Simple Phone Detector Circuit.
Project PCB Gerber File & PCB Ordering Online
If you don’t want to assemble the circuit on a breadboard and you want PCB for the project, then here is the PCB for you. The PCB Board for Mobile Phone Detector is designed using
EasyEDA
online Circuit Schematics & PCB designing tool. The PCB looks something like below.
The device is powered via 4.5V Battery. The Gerber File for the PCB is given below. You can simply download the Gerber File and order the PCB from
ALLPCB
at
1$
only.
Download Gerber File:
Mobile Phone Detector
You can use this Gerber file to order high quality PCB for this project. To do that visit the
ALLPCB
official website by clicking here:
https://www.allpcb.com/
You can now upload the Gerber File by choosing the Quote Now option. From these options, you can choose the Material Type, Dimensions, Quantity, Thickness, Solder Mask Color and other required parameters.
After filling all details, select your country and shipping method. Finally you can place the order.